// Set epiration time.
var exp = new Date();										//set new date object
exp.setTime(exp.getTime() + (1000 * 60 * 60 * 24 * 30));	//set it 30 days ahead
// This function sets a cookie.
function setCookie(name, value, expires) {
	document.cookie = name + "=" + escape(value) + "; path=/" + ((expires == null) ? "" : "; expires=" + expires.toGMTString());
}
// This function retrieves a cookie.
function getCookie (name) {
    var dc = document.cookie;
    var cname = name + "=";

    if (dc.length > 0) {              
		begin = dc.indexOf(cname);       
			if (begin != -1) {           
			begin += cname.length;       
			end = dc.indexOf(";", begin);
				if (end == -1) end = dc.length;
				return unescape(dc.substring(begin, end));
			} 
		}
		return null;
}
// This function deletes a cookie.
function delCookie(name) {
	document.cookie = name + "=; expires=Thu, 01-Jan-70 00:00:01 GMT" +  "; path=/";
}